Workers' pleas for exemption

The Mayor granted basic exemption for "essential" categories such as emergency services, buses, and taxis. However, his office has been inundated with pleas from other groups. They include:

? Teachers: salary from £19,000. They often need to be at work early and they also have evening meetings.

? Firefighters: salary from £20,000. Matt Wrack, of the Fire Brigades' Union, says: "They do an essential job 24 hours a day, 365 days a year."

? Disabled people: badge holders living in London are exempt but those outside are not. Douglas Campbell of the Disabled Drivers' Association says: "Public transport is not an option for severely disabled people."

? RSPCA officers: salary from £15,000. The charity has 56 officers in London, and each has a van for work. Last year they dealt with 887 incidents within the congestion charge zone.

? Nurses: from £18,000. Night shifts often mean no public transport is available. A congestion charge will make existing nursing shortages even worse, they say.

? Hospital cleaners: £9-11,000. They often work "graveyard" shifts when it is quieter and easier to clean.

? Paramedics: from £20,000. They work anti-social shifts doing an essential job, they say.

? Health visitors: from £25,000. "Most work in the community, meeting patients at their home, work, clinics or drop-in centres. Cars are essential," says the Alliance for Health Professionals.

? Emergency social workers: from £23,000. "Duty workers are frequently called out at night if a child is reported being abused or has come to police attention," says Unison.